Various industrial plants present unique problems against continuous operation as a consequence of objectionable build-up of materials within the confined interiors of the manufacturing premises. For example, in the operation of cement kilns, objectionable cement stalactite-like formations build up within the interior of the kiln. Operators of such kilns resort to the use of 8-gauge shotgun slugs, which are unusually heavy loads, to dislodge such formations. Such heavy loads require the use of unusually large quantities of propellant in the shotshell. Such unusually large quantities of propellant, in turn, require increased primer ignition capability.
For many years, small arms ammunition primers have been made by using a heavy metal organic explosive as the main explosive component, with a heavy metal oxidizer and fuel. However, since 1985, there has been a growing interest in heavy-metal-free primers for environmental and personal health reasons.
Several centerfire and rimfire primer mix formulations that are heavy-metal-free and toxic metal free have been patented. However, there have not been any heavy-metal and toxic metal free primer mixes designed especially for shotshells. This may be because shotguns are normally fired out of doors and not used for indoor range shooting and hence there has not been a demand for such a product. In any event, I am not aware of any heavy-metal-free primer mix for shotshells.
It is noteworthy that a shotshell primer requires much more energy as propellant-igniting ability than a centerfire rifle or pistol primer, especially for heavy 3xc2xdxe2x80x3 12 gauge, 10 gauge and 8 gauge loads.
It is common practice today, however, to utilize antimony sulfide as the fuel, and barium nitrate as the oxidizer, in the priming mix needed to adequately burn the propellant. While these materials perform adequately to dislodge the objectionable accumulations of cement, etc., they produce toxic exhaust vapors which are highly objectionable. The invention herein is directed toward obviating the presence of such toxic vapors. To the best of my knowledge, no one has heretofore designed a non-toxic, heavy-metal-free primer mix for heavily loaded shotshells.
My new primer mix is both non-toxic and heavy-metal-free and is equally adequate (as compare to the above toxic primer) in supporting the burn of the increased volumes of propellant. Since it does not include any of the various lead, barium, or antimony compounds, my new primer mix is substantially more preferable over that in common use today.
My new non-toxic heavy-metal-free primer mix is designed for effective use in heavy-load shotshells in which the slug (load) is unusually heavy, because the work which it will be called upon to do is unusually difficult.
The method of blending the components of the above mix and their specific amounts are set forth in detail hereinafter. The mix is characterized by the use of a percussion-sensitive organic primary explosive in combination with a secondary explosive such as highly shock sensitive PETN and powdered aluminum, the latter two in about equal amounts which are substantially greater than those ordinarily utilized in primers. Tetracene is used as a sensitizer, fine glass as a frictionator, and potassium nitrate and ferric oxide as oxidizers. The method of blending these components is set forth in detail hereinafter.
The inventions include the use of DDNP as the primary explosive, together with about one-half as much by weight of PETN, and powdered aluminum in an amount by weight about equal to that of the PETN.
A more detailed description of the components, together with the ranges of their amounts is comprised of about 22-32% by weight of DDNP; 3-5% by weight of tetracene; 13-17% by weight of powdered aluminum; 13-17% by weight of PETN; 8-12% by weight of fine glass; 15-19% by weight of potassium nitrate; 8-12% by weight of ferric oxide; and about 1% by weight of gum tragacanth.